From e74df61ca0a364f84c3a365e720848ff24ceebd8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Szab=C3=B3=20Iv=C3=A1n?= <ivan.szabo.sis@gmail.com>
Date: Fri, 24 Jan 2025 14:37:21 +0100
Subject: [PATCH] NFC Test vol 1.

---
 src/WorkFlowCheck.MAUI/AppShell.xaml          |   2 +
 src/WorkFlowCheck.MAUI/MainPage.xaml          |   6 +
 src/WorkFlowCheck.MAUI/MainPage.xaml.cs       |   4 +
 .../Pages/NFC/NFCTestPage.xaml                |  12 ++
 .../Pages/NFC/NFCTestPage.xaml.cs             | 130 ++++++++++++++++++
 .../Pages/Security/LoginPage.xaml.cs          |   2 +-
 .../Platforms/Android/AndroidManifest.xml     |   2 +
 .../Platforms/Android/MainActivity.cs         |  23 ++++
 .../WorkFlowCheck.MAUI.csproj                 |   3 +
 9 files changed, 183 insertions(+), 1 deletion(-)
 create mode 100644 src/WorkFlowCheck.MAUI/Pages/NFC/NFCTestPage.xaml
 create mode 100644 src/WorkFlowCheck.MAUI/Pages/NFC/NFCTestPage.xaml.cs

diff --git a/src/WorkFlowCheck.MAUI/AppShell.xaml b/src/WorkFlowCheck.MAUI/AppShell.xaml
index a6ab65e..4a53744 100644
--- a/src/WorkFlowCheck.MAUI/AppShell.xaml
+++ b/src/WorkFlowCheck.MAUI/AppShell.xaml
@@ -5,10 +5,12 @@
     xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
     xmlns:local="clr-namespace:WorkFlowCheck.MAUI"
     xmlns:security="clr-namespace:WorkFlowCheck.MAUI.Pages.Security"
+    xmlns:nfc="clr-namespace:WorkFlowCheck.MAUI.Pages.NFC"
     Shell.FlyoutBehavior="Disabled"
     Title="WorkFlowCheck.MAUI">
 
     <ShellContent Title="Home" ContentTemplate="{DataTemplate local:MainPage}" Route="MainPage" />
     <ShellContent Title="Login" ContentTemplate="{DataTemplate security:LoginPage}" Route="LoginPage" />
+    <ShellContent Title="NFC Test" ContentTemplate="{DataTemplate nfc:NFCTestPage}" Route="NFCTestPage" />
 
 </Shell>
diff --git a/src/WorkFlowCheck.MAUI/MainPage.xaml b/src/WorkFlowCheck.MAUI/MainPage.xaml
index aac399c..2377a26 100644
--- a/src/WorkFlowCheck.MAUI/MainPage.xaml
+++ b/src/WorkFlowCheck.MAUI/MainPage.xaml
@@ -37,6 +37,12 @@
                 SemanticProperties.Hint="Counts the number of times you click"
                 Clicked="OnCounterClicked"
                 HorizontalOptions="Fill" />
+            <Button
+                x:Name="NFCTestBtn"
+                Text="NFC Test" 
+                SemanticProperties.Hint="Test NFC capability"
+                Clicked="OnButtonNFCTest"
+                HorizontalOptions="Fill" />
         </VerticalStackLayout>
     </ScrollView>
 
diff --git a/src/WorkFlowCheck.MAUI/MainPage.xaml.cs b/src/WorkFlowCheck.MAUI/MainPage.xaml.cs
index 7aeb956..44ece58 100644
--- a/src/WorkFlowCheck.MAUI/MainPage.xaml.cs
+++ b/src/WorkFlowCheck.MAUI/MainPage.xaml.cs
@@ -44,6 +44,10 @@ namespace WorkFlowCheck.MAUI
                 
             }
         }
+        private async void OnButtonNFCTest(object sender, EventArgs e)
+        {
+            await Shell.Current.GoToAsync("//NFCTestPage");
+        }
     }
 
 }
diff --git a/src/WorkFlowCheck.MAUI/Pages/NFC/NFCTestPage.xaml b/src/WorkFlowCheck.MAUI/Pages/NFC/NFCTestPage.xaml
new file mode 100644
index 0000000..f715f96
--- /dev/null
+++ b/src/WorkFlowCheck.MAUI/Pages/NFC/NFCTestPage.xaml
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             x:Class="WorkFlowCheck.MAUI.Pages.NFC.NFCTestPage"
+             Title="NFCTestPage">
+    <VerticalStackLayout>
+        <Label 
+            Text="Welcome to .NET MAUI!"
+            VerticalOptions="Center" 
+            HorizontalOptions="Center" />
+    </VerticalStackLayout>
+</ContentPage>
\ No newline at end of file
diff --git a/src/WorkFlowCheck.MAUI/Pages/NFC/NFCTestPage.xaml.cs b/src/WorkFlowCheck.MAUI/Pages/NFC/NFCTestPage.xaml.cs
new file mode 100644
index 0000000..370acc0
--- /dev/null
+++ b/src/WorkFlowCheck.MAUI/Pages/NFC/NFCTestPage.xaml.cs
@@ -0,0 +1,130 @@
+using Plugin.NFC;
+using System.Text;
+
+namespace WorkFlowCheck.MAUI.Pages.NFC;
+
+public partial class NFCTestPage : ContentPage
+{
+	public NFCTestPage()
+	{
+		InitializeComponent();
+	}
+    public const string ALERT_TITLE = "NFC";
+    bool _eventsAlreadySubscribed = false;
+    protected override async void OnAppearing()
+    {
+        base.OnAppearing();
+        CrossNFC.Legacy = false;
+        if (CrossNFC.IsSupported)
+        {
+            if (!CrossNFC.Current.IsAvailable)
+                await ShowAlert("NFC is not available");
+             
+            if (!CrossNFC.Current.IsEnabled)
+                await ShowAlert("NFC is disabled");
+
+            await AutoStartAsync().ConfigureAwait(false);
+        }
+        else
+        {
+            await ShowAlert("NFC is not available");
+        }
+    }
+    Task ShowAlert(string message, string title = null) => DisplayAlert(string.IsNullOrWhiteSpace(title) ? ALERT_TITLE : title, message, "OK");
+    async Task AutoStartAsync()
+    {
+        // Some delay to prevent Java.Lang.IllegalStateException "Foreground dispatch can only be enabled when your activity is resumed" on Android
+        await Task.Delay(500);
+        await StartListeningIfNotiOS();
+    }
+    async Task StartListeningIfNotiOS()
+    {
+        
+        await BeginListening();
+    }
+    async Task BeginListening()
+    {
+        try
+        {
+            MainThread.BeginInvokeOnMainThread(() =>
+            {
+                SubscribeEvents();
+                CrossNFC.Current.StartListening();
+            });
+        }
+        catch (Exception ex)
+        {
+            await ShowAlert(ex.Message);
+        }
+    }
+    void SubscribeEvents()
+    {
+        if (_eventsAlreadySubscribed)
+            UnsubscribeEvents();
+
+        _eventsAlreadySubscribed = true;
+
+        CrossNFC.Current.OnMessageReceived += Current_OnMessageReceived;
+        //CrossNFC.Current.OnMessagePublished += Current_OnMessagePublished;
+        //CrossNFC.Current.OnTagDiscovered += Current_OnTagDiscovered;
+        //CrossNFC.Current.OnNfcStatusChanged += Current_OnNfcStatusChanged;
+        //CrossNFC.Current.OnTagListeningStatusChanged += Current_OnTagListeningStatusChanged;
+
+        
+    }
+    void UnsubscribeEvents()
+    {
+        CrossNFC.Current.OnMessageReceived -= Current_OnMessageReceived;
+        //CrossNFC.Current.OnMessagePublished -= Current_OnMessagePublished;
+        //CrossNFC.Current.OnTagDiscovered -= Current_OnTagDiscovered;
+        //CrossNFC.Current.OnNfcStatusChanged -= Current_OnNfcStatusChanged;
+        //CrossNFC.Current.OnTagListeningStatusChanged -= Current_OnTagListeningStatusChanged;
+
+        
+
+        _eventsAlreadySubscribed = false;
+    }
+    async void Current_OnMessageReceived(ITagInfo tagInfo)
+    {
+        if (tagInfo == null)
+        {
+            await ShowAlert("No tag found");
+            return;
+        }
+
+        // Customized serial number
+        var identifier = tagInfo.Identifier;
+        var serialNumber = NFCUtils.ByteArrayToHexString(identifier, ":");
+        var title = !string.IsNullOrWhiteSpace(serialNumber) ? $"Tag [{serialNumber}]" : "Tag Info";
+
+        if (!tagInfo.IsSupported)
+        {
+            await ShowAlert("Unsupported tag (app)", title);
+        }
+        else if (tagInfo.IsEmpty)
+        {
+            await ShowAlert("Empty tag", title);
+        }
+        else
+        {
+            var first = tagInfo.Records[0];
+            await ShowAlert(GetMessage(first), title);
+        }
+    }
+    string GetMessage(NFCNdefRecord record)
+    {
+        var message = $"Message: {record.Message}";
+        message += Environment.NewLine;
+        message += $"RawMessage: {Encoding.UTF8.GetString(record.Payload)}";
+        message += Environment.NewLine;
+        message += $"Type: {record.TypeFormat}";
+
+        if (!string.IsNullOrWhiteSpace(record.MimeType))
+        {
+            message += Environment.NewLine;
+            message += $"MimeType: {record.MimeType}";
+        }
+
+        return message;
+    }
+}
\ No newline at end of file
diff --git a/src/WorkFlowCheck.MAUI/Pages/Security/LoginPage.xaml.cs b/src/WorkFlowCheck.MAUI/Pages/Security/LoginPage.xaml.cs
index 92ec965..0de37b0 100644
--- a/src/WorkFlowCheck.MAUI/Pages/Security/LoginPage.xaml.cs
+++ b/src/WorkFlowCheck.MAUI/Pages/Security/LoginPage.xaml.cs
@@ -21,7 +21,7 @@ public partial class LoginPage : ContentPage
             await DisplayAlert("Success", "You are now logged in.", "OK");
 
             // Visszatérés a MainPage-re
-            await Navigation.PopAsync();
+            await Shell.Current.GoToAsync("//MainPage");
         }
         else
         {
diff --git a/src/WorkFlowCheck.MAUI/Platforms/Android/AndroidManifest.xml b/src/WorkFlowCheck.MAUI/Platforms/Android/AndroidManifest.xml
index e9937ad..db3fcde 100644
--- a/src/WorkFlowCheck.MAUI/Platforms/Android/AndroidManifest.xml
+++ b/src/WorkFlowCheck.MAUI/Platforms/Android/AndroidManifest.xml
@@ -3,4 +3,6 @@
 	<application android:allowBackup="true" android:icon="@mipmap/appicon" android:roundIcon="@mipmap/appicon_round" android:supportsRtl="true"></application>
 	<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
 	<uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.NFC" />
+    <uses-feature android:name="android.hardware.nfc" android:required="false" />
 </manifest>
\ No newline at end of file
diff --git a/src/WorkFlowCheck.MAUI/Platforms/Android/MainActivity.cs b/src/WorkFlowCheck.MAUI/Platforms/Android/MainActivity.cs
index 8bf9c71..a4d463b 100644
--- a/src/WorkFlowCheck.MAUI/Platforms/Android/MainActivity.cs
+++ b/src/WorkFlowCheck.MAUI/Platforms/Android/MainActivity.cs
@@ -1,6 +1,8 @@
 using Android.App;
+using Android.Content;
 using Android.Content.PM;
 using Android.OS;
+using Plugin.NFC;
 
 namespace WorkFlowCheck.MAUI
 {
@@ -12,5 +14,26 @@ namespace WorkFlowCheck.MAUI
             SecureStorage.Default.Remove("WFCUser");
             base.OnDestroy();
         }
+        protected override void OnCreate(Bundle savedInstanceState)
+        {
+            // Plugin NFC: Initialization before base.OnCreate(...) (Important on .NET MAUI)
+            CrossNFC.Init(this);
+
+            base.OnCreate(savedInstanceState);
+        }
+        protected override void OnResume()
+        {
+            base.OnResume();
+
+            // Plugin NFC: Restart NFC listening on resume (needed for Android 10+) 
+            CrossNFC.OnResume();
+        }
+        protected override void OnNewIntent(Intent intent)
+        {
+            base.OnNewIntent(intent);
+
+            // Plugin NFC: Tag Discovery Interception
+            CrossNFC.OnNewIntent(intent);
+        }
     }
 }
diff --git a/src/WorkFlowCheck.MAUI/WorkFlowCheck.MAUI.csproj b/src/WorkFlowCheck.MAUI/WorkFlowCheck.MAUI.csproj
index 5a3df93..faa7492 100644
--- a/src/WorkFlowCheck.MAUI/WorkFlowCheck.MAUI.csproj
+++ b/src/WorkFlowCheck.MAUI/WorkFlowCheck.MAUI.csproj
@@ -73,6 +73,9 @@
 	</ItemGroup>
 
 	<ItemGroup>
+	  <MauiXaml Update="Pages\NFC\NFCTestPage.xaml">
+	    <Generator>MSBuild:Compile</Generator>
+	  </MauiXaml>
 	  <MauiXaml Update="Pages\Security\LoginPage.xaml">
 	    <Generator>MSBuild:Compile</Generator>
 	  </MauiXaml>